Collaborative Research: Self-Sustaining Thermochemical Pumping and Power Generation At Mesoscales

CBET-1403405/1402142Ahn(锡拉丘兹)/Ronney(南加州大学)便携式电子设备(PED)，如手机和笔记本电脑，对电力的需求不断增长，但它们使用的电池作为碳氢燃料每磅仅提供1%至2%的能量。由于碳氢燃料的能量密度很高，它们是大规模发电的首选燃料。然而，这并不是小规模的，因为工程师们无法将内燃机或蒸汽机的规模缩小到为PED发电所需的尺寸。微型燃料电池(将燃料直接转化为电能)已被用于为PED供电，但只有通过使用氢或甲醇等燃料才能成功，这些燃料存在安全问题和/或如果包括储罐的重量，每磅能量非常低。目前的工作建议使用丙烷和丁烷，这两种燃料都是一次性打火机中使用的易于储存的高能量密度燃料，用于为PED发电，并提供了一种非常简单、多功能的系统来向设备提供空气。这项工作的结果可能会对电能储存密度超过电池10倍的PED产生重大影响。此外，将空燃料盒处置在垃圾填埋场比处置含有有毒金属的旧电池更可取。这项工作将涉及本科生和工程学研究生，并通过锡拉丘兹和美国加州大学的课程教育K-12学生。便携式电子设备对电力的需求不断增长，但电池提供的能量密度仅为碳氢燃料的1%至2%。由于热损失、摩擦和难以以足够的精度在小范围内制造零件，内燃机和发电机的规模缩小到MEMS规模的努力一直未获成功。PIS建议使用(1)用于燃料和空气泵的纳米多孔材料中的热蒸腾；(2)在室温点火的铂和金催化剂上燃烧；以及(3)不需要在燃料和氧化剂之间密封或分离的单室固体氧化物燃料电池，以便在热发汗泵内发电。任意形状的反应堆将使用采用多孔烧结不锈钢独特的三维打印技术建造的部件来建造。采用原位FTIR/气相色谱分析方法，研究了负载型Au纳米粒子对碳氢化合物氧化的低温点火活性。为了确定哪些性质对低温氧化影响最大，将通过扫描电子显微镜评估它们的表面结构修饰，并通过X射线光电子能谱评估它们的化学修饰。研究了离子取代对双钙钛矿结构性能的影响，并考察了几种贵金属氧化物负载电催化剂的催化性能。一种高纯度的Gd掺杂CeO_2源有望提高电解液的电导率，同时保持薄膜电解液燃料电池的可加工性。设想的系统是自给自足的，将抽水和发电集成在一个设备中，没有移动部件，只使用碳氢燃料提供的热能和电化学能(即，它没有寄生电能损失)。这项研究还可以将其应用于其他需要气体加压或真空泵的系统，例如微型气相色谱仪或有毒化学试剂传感器。

CBET-1403405/1402142Ahn (Syracuse)/Ronney (USC)Portable electronic devices (PEDs) such as cell phones and laptop computers have ever-growing needs for electrical power, yet the batteries they use provide only 1 to 2% energy per pound as hydrocarbon fuels. Because hydrocarbon fuels pack high energy densities, they are the fuel of choice for power generation at large scales. However, this is not done at small scales since engineers have been unable to scale internal combustion or steam engines down to the sizes required to generate electricity for PEDs. Tiny fuel cells (which convert fuel directly into electricity) have been used to power PEDs, but have only succeeded by using fuels such as hydrogen or methanol which have safety issues and/or very low energy per pound when the weight of the storage tank is included. The present work proposes to use propane and butane, the same easily-stored, high energy density fuels used in disposable lighters, for generating power for PEDs and provides a very simple, versatile system for supplying air to the device. The results of this work could have a significant impact on PEDs with electrical energy storage densities exceeding batteries by a factor of 10. Moreover, disposal of empty fuel cartridges in landfills is preferable to disposal of used batteries containing toxic metals. This work will involve undergraduate and graduate engineering students and also educate K-12 students through programs at Syracuse and USC.Portable electronic devices have ever-growing needs for electrical power, yet batteries provide only 1 to 2% of the energy density of hydrocarbon fuels. Scale-down of internal combustion engines and electrical generators to MEMS scales has been unsuccessful due to issues with heat losses, friction and the difficulty of manufacturing parts at small scales with sufficient precision. The PIs propose to generate electrical power from hydrocarbon fuels at small scales using (1) thermal transpiration in nanoporous materials for fuel and air pumping; (2) combustion on Pt- and Au- catalysts with room-temperature ignition; and (3) single-chamber solid oxide fuel cells requiring no seals or separation between fuel and oxidant for power generation within the thermal transpiration pump. Reactors of arbitrary shape will be constructed using parts built using a unique 3-dimensional printing technology for porous sintered stainless steel. The activity of supported Au nanoparticles for low-temperature ignition of hydrocarbon oxidation will be measured using in-situ FTIR/Gas Chromatography analysis. To determine what property has the most impact on low-temperature oxidation, their surface structure modifications will be assessed via Scanning Electron Microscopy and their chemical modifications via X-ray Photoelectron Spectroscopy. The effects of ion substitution on the properties of double-perovskite structures will be investigated and the catalytic behavior of several precious-metal, oxide-supported electrocatalysts will also be examined. A high purity source of gadolinia-doped-ceria is expected to increase the electrolyte conductivity, yet retain the processability for thin-film electrolyte fuel cell fabrication. The envisioned system is self-contained, has pumping and power generation integrated into one device, has no moving parts and operates only on thermal and electrochemical energy supplied by hydrocarbon fuels (i.e., it has no parasitic electrical energy losses). This research could also enable spin-off applications to other systems requiring gas pressurization or vacuum pumping, e.g. micro gas chromatographs or toxic chemical agent sensors.